ELISHA MITCHELL SCIENTIFIC SOCIETY. J I 



holes. Through one of these a calcium chloride tube was inserted, 

 through the other a glass tube with a glass rod working tightly in it 

 and bound to it means of rubber lubing so as to be air-tight. The 

 calcium chloride tube was 250 mm. long, and was filled with freshly 

 dried calcium chloride. Inside the bell-jar, a glass acid-holder was 

 filled with concentrated sulphuric acid and on a triangle placed over 

 it wslS supported a watch glass containing carbon disulphide purified 

 by tlie method of Cloez (Compt. rend. 69, 1356). The glass rod had 

 attached to it by a bit of wax a strip of filter p^aper 25 mm. broad, 

 100 mm. long, which had been previously dried in an air-bath for 

 two hours at lOO'' — lOo'^ c. After this was put in the bell-jar, the 

 latter was fitted tightly to the glass plate and the whole allowed to 

 stand about thirty minutes so that every trace of moisture might be 

 removed from the enclosed air. At the expiration of this time, the 

 slip of paper was lowered by the movable rod until it touched the 

 carbon disulphide. The liquid rose rapidly in the pores of the paper, 

 but even after some minutes no sign of the solid incrustations could 

 be seen. As the confined space might have interfered with the 

 evaporation, an aspirator was attached to the calcium chloride tube, 

 but no formation of the solid could be induced. The sulphuric ac id 

 was then taken from the jar and water substituted for it. The solid 

 commenced to form almost immediately after the lowering of the 

 paper. The liquid did not rise quite so high as in the first case, and 

 aspirating increased the rate of formation but slightly. If the as- 

 piration was continued until the ja,r was filled with aqueous vapor, 

 the solid formation suddenly and completely melted away. 



Several difi'erent ways were tried of forming this hydrate. First, 

 carbon disuljjhide mixed with about 25 per cent, of water, in a test 

 tube, was placed in a mixture of ice and hydrochloric acid ( — 2'6° c), 

 and for purposes of comparison a tube containing distilled water 

 wa- placed beside it. The first tube became very milky and turbid 

 and was frozen to an opaque solid ; in the second tube the water 

 remained transparent until completely frozen. A second tube of 

 water and the disulphid'^ was stirred whilst freezing, so as to freeze 

 only on the sides and leave a channel open from the bottom to top. 

 All that refused to freeze was poured out, the tube corked and its 

 contents melted. After melting, a layer of disulphide was observed 

 beneath the water. Of course no great reliance can be placed on 

 such an experiment alone, as the oil may have been mechanicallv 

 -entangled and retained. Again, if a few c.c. of carbon disulphide 

 be poured through 2-3 cm. of 90 per cent, alcohol in a tube the two 

 form clear and distinct layers. Let this tube gently down into a 



